HIV Drug Not Tied to Premature Births

by Ed Susman Contributing Writer, MedPage Today

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Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

The study found that pregnant HIV-infected women treated with a lopinavir/ritonavir (Kaletra)-based antiretroviral regimen are at no greater risk of delivering a preterm baby than similar pregnant women given an efavirenz (Sustiva)-based treatment.

Note that no difference was found in the risk of low birth weight and no difference in median gestational age between women who received lopinavir/ritonavir compared with efavirenz (EFV)-based antiretroviral therapy.

ATLANTA -- Pregnant HIV-infected women treated with a lopinavir/ritonavir (Kaletra)-based antiretroviral regimen are at no greater risk of delivering a preterm baby than similar pregnant women given an efavirenz (Sustiva)-based treatment, researchers said here.

In a study conducted in Uganda, the overall risk of preterm birth was 14.9%, according to Deborah Cohan, MD, MPH, of the University of California San Francisco.

"It was 15.9% in the lopinavir/ritonavir arm and 13.6% in the efavirenz arm," with a P value of 0.65, she said in a press briefing at the annual Conference on Retroviruses and Opportunistic Infections. "The Ugandan national average for preterm birth is 13.6%."

"Overall, the goal should be to get HIV-infected pregnant women initiated into care early, and initiate an antiretroviral therapy in a timely fashion," Cohan told MedPage Today.

Her study included 391 Ugandan women who were HIV-infected and in their second trimester of pregnancy.

"There has been conflicting observational data on preterm birth with combination antiretroviral therapy in general," Cohan explained. "To answer this question we did a secondary analysis of the PROMOTE trial, a randomized trial among women randomized to a lopinavir/ritonavir-containing antiretroviral therapy or to an efavirenz regimen."

The women started on antiretrovirals during pregnancy between 12 and 28 weeks of gestation, and continued on this regimen through 1 year of breastfeeding.

"We found no significant difference in the percentage of preterm birth defined as 37 weeks; we found no significant difference in the risk of very preterm birth defined as less than 32 weeks of gestation," she said in reporting the results of her late-breaker poster presentation.

"We found no difference in the risk of low birth weight and no difference in median gestational age," Cohan continued. "Moreover, the risk of preterm birth was quite comparable to what we see in the general Ugandan population."

Median gestational age overall was 39 weeks; among lopinavir/ritonavir-treated women the median gestational age was 38.7 weeks; among the women on efavirenz the median gestational age was 39.2 weeks.

Low birthweight -- less than 2,500 grams (5.5 lbs.) -- was observed among 16.8% of all babies born in the study, 17.3% among those on lopinavir/ritonavir, and 16.3% among those on efavirenz (P=0.88 for difference between the two drug regimens).

The incidence of very preterm birth -- babies with less than 32 weeks of gestation -- was 1.7% overall; 1.1% with lopinavir/ritonavir; and 2.13% among babies whose mothers were exposed to efavirenz (P=0.45 for difference between the two drug regimens).

"I am comfortable in my own practice in prescribing protease inhibitors to pregnant women with HIV infection," Cohan said. "I have not observed any great increased risk of preterm births."

Other studies that have shown an increased risk "may not have analyzed confounders such as smoking, their risk behaviors, and other factors that led them to be on first semester protease inhibitors," she said. "These results are that much more reassuring that those protease inhibitors are not harmful in pregnancy."

"I agree that this is a reassuring report," said Scott Hammer, MD, professor of medicine at Columbia University in New York City, who moderated the press briefing.

"In the U.S. we avoid efavirenz in the first trimester of pregnancy," he told MedPage Today.

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